Field of the Invention
The present invention relates to a rod stiffener for a bumper of a car, and more particularly, to a rod stiffener for a bumper of a car which is coupled to a lower portion of a bumper beam of the car to improve shock absorption capability when the car collides and is improved to simultaneously implement stiffness and flexibility as well as weight lightening and cost reduction while maximally guaranteeing safety of passengers.
Description of Related Art
In general, a bumper beam for a car, which is to be elastically deformed when the car collides at a low speed to minimize physical damage to the car, may be a buffer disposed at a front and rear of the car so that it may absorb shock when the car collides with other cars or a fixed body in order to aim for safety of passengers and minimize deformation of a car body at the same time.
In case of increasing strength of the above-mentioned bumper beam, weight and cost are rapidly increased, and in case of decreasing weight and cost, strength is decreased, such that a function thereof may be insufficiently performed.
Therefore, a fiber reinforced thermoplastic resin having increased strength while using weight lightening material, for example, a glass fiber mat thermoplastic (GMT) material has been developed.
Here, the GMT material, which is a composite material having a plate shape consisting of a polypropylene resin, which is a general purpose resin, and a glass fiber mat reinforcement, is a novel material having excellent adhesion with the resin because polypropylene in a melted state extruded through a T-Die, particularly, and glass fiber non-woven mat are directly clipped, exhibiting excellent strength compared to existing materials used in prior art because strength of glass itself is reinforced by a mat shape, and having characteristics such as light weight property and a degree of freedom of design, which are unique properties of plastic as well as high productivity, recyclability, and the like, based on the thermoplastic resin.
The above-mentioned GMT material is highlighted as a next generation composite material to be used for the bumper beam, a seat back, an undercover, and the like because it may be weight lightened, has excellent absorptiveness of collision energy, has an improved degree of freedom of a design, and has excellent assembly properties, corrosion resistance, stiffness, stability, sound insulation property, dust elimination property, elasticity, shock resistance, and the like.
Meanwhile, in order to satisfy pedestrian regulations for minimizing injury when the car collides with a pedestrian, as shown in FIG. 1, a rod stiffener 200 coupled to a lower portion of a bumper beam 100 is disclosed.
However, since the rod stiffener according to the related art is disclosed only as a part for simply satisfying the pedestrian regulations rather than an optimal design, it increases weight according to an addition thereof and is at a level simply decreasing a degree of bending of a knee angle of the pedestrian, and since a structure and dynamic approach is not performed in view of stiffness and flexibility, it causes weight to be increased.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.